1. Field of the Invention
The invention relates to a method for making ice in a compact icemaker. More particularly, the invention relates to optimizing the ice cube production by more accurately determining the time for the ice cubes are formed.
2. Description of the Related Art
Household refrigerator/freezers are commonly sold with a compact icemaker, which is a great convenience to the consumer. Icemakers can be generally categorized into two classes based on the manner in which the ice cubes are harvested from the ice cube tray. The most common method is for the ice cubes to be formed in an ice cube tray incorporating multiple ejectors that forcibly eject the ice cubes from each of the ice cube recesses in the ice cube tray, typically from a metal mold. The other class of icemakers has ice cube trays that are inverted to expel the ice cubes from the ice cube recesses of the ice cube tray. These icemakers are usually made from a plastic material and are generally referred to as flextrays.
In the metal mold class of icemakers, it is common to use a resistance wire formed in the ice cube tray to heat the ice cube tray to melt the ice cubes at their interface with the ice cube tray thereby enhancing the likelihood that the ice cubes can be successfully harvested from the ice cube tray.
In the flextray version icemaker, generally a rotational force is applied to the mold to impart a stress by flexing the tray to generate enough pressure on the cube to forcibly remove the cubes from the mold. A heating element is generally not used with the flextray. The elimination of the heater makes the icemaker more energy efficient. Along with the energy efficiency, the resistance wire approaches are undesirable due to their cyclic temperature loading of the freezer compartment. The higher temperature swings of the freezer result in increased occurrences and severity of freezer burn as well as an increase in sugar migration within products. The sugar migration specifically shows up in ice cream products and is highly undesirable.
Even with devices such as the ejectors and heaters to aid in the harvesting of the ice cubes, it is still a common problem for the ice cubes to be stuck in the tray, which is highly undesirable. A stuck ice cube can result in an over-fill condition for the ice cube tray since the ice cube tray is typically filled with a predetermined charge of water based on the total volume of the ice cube recesses. In an over-fill condition, the excess water will spread across the multiple ice cube recesses and upon its freezing form a layer of ice connecting the individual ice cubes, which further increases the likelihood that the ice cubes will not be harvested.
If the icemaker has a mechanism for detecting such an over fill condition, the icemaker is shut down until the stuck ice is removed, resulting in a loss of ice production for the consumer. If the icemaker does not have an over fill detection mechanism, the icemaker will continue to introduce water into the ice cube tray, which will eventually flow into the freezer to form a large block of ice, which is a great inconvenience to the consumer, especially if the ice forms on items contained within the freezer.
In the flextray icemaker, the system repeatedly stresses the mold to a high level to guarantee ice cube release. This cyclic high stress has a degrading effect on the plastic and causes failure of cubes to release or even worse a breakage of the mold. Without proper cube release an overfill event will occur. With a breakage of the mold an even worse case of continuous water flow into the product can occur until it is sensed or the consumer intervenes.
It is still desirable to have an icemaker capable of reliably producing and harvesting ice cubes.